Patent GB-721447-A (GB)
Title: Improvements in or relating to a method of making laminated structures
Inventor: LEADER SIDNEY ARTHUR
IPC: C09J4/00
Filed: 1951-09-05
Abstract: Sheet material impregnated or coated with a thermoplastic polymer and benzoyl or lauroyl peroxide is bonded to like sheet material or to another surface by wetting with a polymerizable liquid ester compatible with the polymer and polymerizable by the peroxide and a tertiary amine which will react with the peroxide with evolution of heat and the treated layers are placed in contact until a bond is formed.  The thermoplastic polymer (preferably a polyacrylic acid ester) and the peroxide may be applied in a solvent such as a ketone, an aromatic hydrocarbon or a chlorinated paraffin (acetone, methyl ethyl ketone, chloroform and methylene chloride are specified) or as a 30 per cent aqueous dispersion.  The weight of peroxide used may be 3 to 20 per cent based on the weight of the polymer.  The sheet material may be textile fabric, paper, cardboard, wood veneer, wire gauze or fibre glass.  Acrylic acid esters and polymerizable polyester resins may be used as the liquid ester, dimethyl-p-toluidine and dimethyl aniline being the preferred tertiary amines.  The wetting liquid may contain an antioxidant stabilizer such as hydroquinone or ascorbic acid.  A plasticizer such as dimethyl phthalate may be added to the impregnating solution or to the wetting liquid.  In an example fibre glass fabric is immersed in a solution of polymethyl methacrylate and benzoyl peroxide in acetone and dried.  The treated fabric is formed into a wrist splint of six layers.  The layers are wetted with methyl methacrylate monomer containing dimethyl-p-toluidine and ascorbic acid and applied to the wrist to form a splint.  The splint after cutting for removal can be replaced and joined by a strip of impregnated fabric wetted as described above.ALSO:Surgical splints are made by impregnating or coating sheet material with a thermoplastic polymer and benzoyl or lauroyl peroxide is bonded to like sheet material or to another surface by wetting with a polymerisable liquid ester compatible with the polymer and polymerisable by the peroxide and a tertiary amine which will react with the peroxide with evolution of heat and the treated layers are placed in contact until a bond is formed.  The thermoplastic polymer (preferably a polyacrylic,acid ester) and the peroxide may be applied in a solvent such as a ketone, an aromatic hydrocarbon or a chlorinated paraffin (acetone, methyl ethyl ketone, chloroform and methylene chloride are specified) or as a 30 per cent. aqueous dispersion.  The weight of peroxide used may be 3 to 20 per cent based on the weight of the polymer. The sheet material may be textile fabric, paper, cardboard, wood veneer, wire gauze or fibre glass.  Acrylic esters and polymerisable polyester resins may be used as the liquid ester, dimethyl-p-toluidine and dimethyl aniline being the preferred tertiary amines.  The wetting liquid may contain an antioxidant stabiliser such as hydroquinone or ascorbic acid.  A plasticizer such as dimethyl phthalate may be added to the impregnating solution or to the wetting liquid.  In an example fibre glass fabric is immersed in a solution of polymethyl methyacrylate and benzoyl peroxide in acetone and dried.  The treated fabric is formed into a wrist splint of six layers.  The layers are wetted with methyl methacrylate monomer containing dimethyl-p-toluidine and ascorbic acid and applied to the wrist (previously coated with a silicone grease) to form a splint.  The splint after cutting for removal can be replaced and joined by a strip of impregnated fabric wetted as described above.